This invention relates to a steering wheel, in which the hub and spokes are made of synthetic thermoplastic material and just like the rim are covered with a layer of a deformable plastic material.
Such a steering wheel is known, e.g., from German Utility Model 75 31 072 and is much lighter in weight than a conventional steering wheel having a metal skeleton. A decrease in the weight of components of motor vehicles will reduce the fuel consumption so that energy can be saved. Besides, a steering wheel which is lighter in weight represents a smaller mass which is capable of oscillation or rotation so that a more desirable vibratory behavior will be obtained as is desired by the higher comfort requirements. But steering wheels made of thermoplastic material have the disadvantage that they do not entirely comply with the high requirements to be met as regards temperature-stable stiffness, strength and impact strengths, particularly as far as the rim of the steering wheel is concerned. It is also difficult to ensure that the torques which are exerted on the rim of the steering wheel for a steering movement will reliably be transmitted via the hub to the steering column.
For this reason the manufacturers of steering wheels face the object to develop a steering wheel which is light in weight and complies with the requirements of modern motor vehicle engineering. But a saving in weight must not impair the reliability in operation.